Portable water filtration apparatus, such as those sold under the Brita trade mark, include countertop water filters and faucet mounted water filters. These water filters typically include a filter assembly that includes a filtration media, such as activated carbon. These filter assemblies are fitted into the water filters. For example, a filter assembly may be fitted onto or into a funnel member coupled to a receiving container (a water reservoir) for collecting liquid, or onto a fixture coupled to a faucet wherein the water from the faucet flows through the fixture prior to being dispensed.
Known filter assemblies generally include a cartridge which houses granulated carbon. For example, U.S. Pat. No. 6,012,232 to Weyrauch and U.S. Pat. No. 6,099,728 to Bairischer describe a cartridge in the form of a closed cup, which has holes on the upper and lower portions through which water passes as it is filtered. The cup houses granulated carbon, and the holes on the upper and lower portions are covered with a sieve cloth to prevent the granulated carbon from escaping. Over time, the granulated carbon in such cartridges becomes spent, and the user must dispose of the cartridge and replace it with a new one.